We propose a symposium to explore the implications of stressful responses as adaptive mechanisms in the lives of humans and animals, instead of as pathology. The discussion of hypotheses concerning the role of stress in adaptive application from researchers with evolutionary, systems and mechanistic perspectives may lay the framework for a new way of looking at stress in human health. Considering stress as a useful and adaptive response, evolutionarily adjusted, may contribute a new viewpoint for comprehension of basic mechanisms and health-related applications. The nervous and endocrine systems play a critical role in allowing organisms to cope with environmental stressors. Although most of what we know about the endocrinology of stress comes from work done in laboratory mammals, recent studies in nonmammalian species have identified adaptive features of stress that do not readily fit into current views on stress as a disorder or disease. This proposal requests support for a two-day symposium aimed at assessing the state of knowledge on the comparative neuroendocrinology of stress and adaptation. The symposium will bring together, for the first time, a group of scientists working on diverse aspects of chemical signaling during stress in mammalian and nonmammalian organisms. Our rationale is to provide a forum for discussing the comparative neuroendocrinology of stress from molecular to behavioral levels, thereby encouraging an integrated approach to the topic. The symposium has three objectives. The first objective is to examine the phylogenetic diversity of the stress response in organisms ranging from invertebrates to mammals. The second goal is to examine comparative aspects of the hypothalamo-hypophysial-adrenal axis related to its role in adaptation. The third goal is to provide an integrative format format in which to discuss the adaptive role of stress in development, reproduction, immune function and behavior. The outcome of the symposium will a) summarize existing knowledge on the comparative endocrinology of stress, b) help in identifying common themes of neural and endocrine integration during stress, and c) broaden existing views of stress and adaptation with respect to basic mechanisms and human health. Thirteen invited speakers will make oral presentations while graduate students or postdoctoral associates will present posters. The symposium will take place at the annual meeting of the Society for Integrative and Comparative Biology January 3rd-7th, 2001, at the Chicago Hilton & Towers, Chicago, IL. The symposium proceedings will be published in the internationally recognized journal American Zoologist. The symposium should be of interest to biomedical researchers, endocrinologists, neurobiologists, physiologists, ecologists and behavioral biologists.